HONOLULU – Not long ago, patients older than 65 years were rarely considered candidates for lung transplantation. But that’s not quite true anymore.
Being elderly is still a relative contraindication, but according to data from the International Society for Heart and Lung Transplantation, an increasing proportion of people older than age 65 are receiving lung transplants, from about 2% in 1995-1999 to about 6% between 2000 and June of 2010.
Dr. Luis F. Angel
Instead of age and the length of time spent on the list waiting for a transplant, candidacy for the procedure is now based on whether patients’ advanced respiratory disease has progressed despite medical therapy, and whether they have a 50% or less chance of survival in the next 2-3 years, Dr. Luis F. Angel explained at the annual meeting of the American College of Chest Physicians.
"Potential candidates must be capable of comprehending the procedure, undergoing the selection process, and waiting the time necessary on the waiting list," said Dr. Angel, director of lung transplantation for the University of Texas Health Science Center at San Antonio.
In a review of the latest criteria, he explained that patients "must also be free of significant medical comorbidities and be sufficiently fit to handle this major surgical procedure and multiple medications post procedure."
The list of absolute contraindications for lung transplantation is lengthy, and includes recent malignancy (other than nonmelanoma skin cancer); infection with HIV; infection with hepatitis B or C with histologic evidence of cirrhosis; active cigarette smoking or substance abuse; severe and untreated psychiatric illness; documented noncompliance with medical care; and absence of a reliable social network.
Relative contraindications, Dr. Angel said, include the clinical state at the moment of notification or referral, such as the presence of hemodynamic instability, excessive physical deterioration, or severe muscle atrophy that impedes performing outpatient rehabilitation. Also taken into account is the need for invasive mechanical ventilation or extracorporeal membrane oxygenation (ECMO) support.
"Colonization by multiresistant or panresistant bacteria, fungus, or mycobacteria is another contraindication," Dr. Angel said, "as are other medical conditions such as coronary artery disease, liver and renal disease, gastroesophageal reflux, or symptomatic osteoporosis, and having a body mass index higher than 30 kg/m2."
Regarding the following specific indication for transplantation, the success rates vary according to the condition:
• COPD/emphysema. In a select group of patients with COPD/emphysema, transplantation provides both survival and quality of life benefits.
Referral criteria include a BODE index of 7-10 points, or at least one of the following: a history of hospitalization for exacerbation associated with acute hypercapnia; pulmonary hypertension or cor pulmonale, or both, despite oxygen therapy; and an FEV1 (forced expiratory volume in 1 second) of less than 20% and either a DLCO (diffusing capacity of the lungs for carbon monoxide) finding of less than 20% or homogenous distribution of emphysema.
• Pulmonary fibrosis. "The natural history of the disease is more predictable, and there are major limitations in effective therapy for this diagnosis," said Dr. Angel of the department of pulmonary and critical care medicine at the university.
Referral criteria, he said, include histologic or radiographic evidence of interstitial pneumonia, and any of the following: a DLCO of less than 39% predicted; a 10% or greater decrement in forced vital capacity during 6 months of follow-up; a decrease in pulse oximetry less than 88% during a 6-minute walk test; honeycombing on high-resolution CT; or development of secondary pulmonary hypertension.
• Cystic fibrosis. Patients with this condition "can get the most significant benefit and prolonged survival with lung transplantation," Dr. Angel said. "Referrals are often delayed, as there is [a] high emotional aspect in the management of these patients and their families."
Referral criteria, he said, include a FEV1 of less than 30% of predicted, or rapidly declining lung function if FEV1 is greater than 30% of predicted, and/or any of the following: increasing oxygen requirements, hypercapnia, and pulmonary hypertension.
• Idiopathic PAH (pulmonary arterial hypertension). "This is one of the most difficult conditions [in which] to determine the right time for transplantation," Dr. Angel said. "Significant improvements with medical therapy and increased awareness of the disease have decreased the number of lung transplants for this indication."
Referral criteria, he said, include persistent New York Heart Association class III or IV on maximal medical therapy; low or declining 6-minute walk test findings; failing therapy with intravenous epoprostenol or equivalent; a cardiac index of less than 2 L/min per square meter, or a right atrial pressure exceeding 15 mm Hg.